1. Field of the Invention
This invention relates to a socket for an electric part and particularly to a socket for an electric part, in which a side portion of a contact of a socket body is provided with a space for no-load insertion of a terminal of the electric part so as to realize a no-load insertion and withdrawal of the electric part in the no-load insertion space. With such a socket, by laterally moving a movable plate mounted on the socket body, a terminal of the electric part mounted on the movable plate is laterally moved from the no-load insertion space and forcefully engaged with the contact in order to realize a contact relation therebetween.
2. Brief Description of the Prior Art
FIG. 8 shows a prior art socket aimed at providing no-load insertion and withdrawal in which a side portion of a contact 3 held by a socket body 1 is provided with a no-load insertion space 4 in order to realize an insertion and withdrawal of the electric part in the no-load insertion space 4. By laterally moving a movable plate 2 mounted on the socket body 1, a terminal 6 of the electric part 5 mounted on the movable plate 2 is laterally moved from the no-load insertion space 4 and forcefully engaged with the contact 3 in order to realize a contact relation therebetween. By laterally moving the movable plate 2 in the reverse direction, the terminal 6 is brought back to the no-load insertion space 4 in order to realize a no-load insertion and withdrawal. The lateral movement of the movable plate 2 is realized by the swinging operation of an operation lever such as a crank lever. In FIG. 8, shafts 7 and 8 mounted on one end of the socket body 1 and one end of the movable plate 2 act as a supporting point and a point of application of the lever, and a transmission shaft 8 is swung about the supporting point 7 by means of the operation lever to provide lateral movement of the movable plate 2.
In the above-mentioned socket for an electric part, a terminal of the electric part mounted on the movable plate is brought to a no-load insertion space in order to allow for a no-load insertion and withdrawal of the electric part. However, the movable plate and the operation lever sometimes become loosened due to vibrations, etc. Therefore, it would become necessary to insert the electric part after the lever had been operated in order to confirm whether the movable plate was correctly positioned. If this confirmation is not carried out when the swinging operation of the operation lever and the movement of the movable plate are imperfect and are not properly moved into the no-load insertion position, the terminal of the electric part, as shown in FIG. 8, is inserted into a contact which is in a closed position. Such insertion into the closed contact causes the terminal and the contact to be deformed. In view of the foregoing, when an electric part is to be inserted into a socket by an automatic machine such as a robot, it is necessary to add a process for confirming that the movable plate is in position to allow no-load insertion. It is undesirable to add such a confirmation step to the operation processes.
The present invention has been accomplished in order to effectively overcome the above-mentioned problems inherent in the prior art.